Accrued Liabilities Long-term liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accrued Liabilities [Abstract]
Liabilities for contracts	$ 16,713	$ 40,148
contract settlement	2,083	0
Capital Lease Obligations, Noncurrent	1,936	0
Accrued Employee Benefits	1,775	2,104
Contract with Customer, Liability, Noncurrent	1,466	7,099
Other Accrued Liabilities, Noncurrent	5,084	5,975
OTHER LONG-TERM LIABILITIES	$ 29,057	$ 55,326	[1]

[1] December 31, 2017 balances were derived from audited consolidated financial statements.